1. Field of the Invention
The invention relates to a color wheel assembly and more particularly, this invention relates to a color wheel assembly, which is used in projection technology.
2. Description of the Related Art
Currently, image projection systems have become popular items in the optoelectronic industry owing to multiple requirements of a system having large display area, small dimension, and thin, light composition.
The popular projection systems are divided into three types including a liquid crystal display (LCD) type, a liquid crystal on silicon (LCoS) type, and a digital light processing (DLP) type, wherein the single-panel LCoS and DLP types advantageously have simplified systems and the following description will take the DLP type as an example.
In a DLP projector, a digital control method and a reflection principle are adopted. For a SCR (Sequential Color Recapture) system, light rays are integrated or converged by a light integration rod and then pass through the color filter of the color wheel, which splits the light rays. The split light rays are then projected onto a digital micro-mirror device (DMD). In this technology, the DMD is used to replace the liquid crystal panel for representing images in the conventional liquid crystal projector. Since the DMD includes several movable micro-mirrors, driving electrodes may control the tilt angle and deflection time of each movable mirror. Then, the light rays may be projected to form an image by switching the reflection directions of the light rays.
In the DP projector, different clamping mechanisms are used to fix the color wheel and the light integration rod in the DLP projector so that the relative position between the color wheel and the light integration rod may be controlled. In the projection system, the position of each optical device through which light rays pass relates to the overall imaging quality of the DLP projector. So, each optical device has to be precisely positioned. Furthermore, when the color wheel is a SCR color wheel, the alignment precision between the color wheel and the light integration rod is more highly required.
However, since the conventional color wheel and light integration rod are fixed to different clamping mechanisms, respectively, the relative position between the color wheel and the light integration rod has to be adjusted. In addition, the relative position between other optical devices and the color wheel and the light integration rod also has to be noted. Consequently, it is necessary to spend longer time to artificially adjust the relative position between the color wheel and the light integration rod as well as that between other optical devices and the color wheel and light integration rod. Meanwhile, the precision of correctly adjusting the relative position between the color wheel and the light integration rod also cannot be easily controlled, and the reproducibility is also poor.
In view of the above-mentioned matters, an object of the invention is to provide a color wheel assembly capable of solving the positioning problems between a color wheel and an optical element.
To achieve the above-mentioned object, the invention provides a color wheel assembly including a color filter, a motor, a fixing element, and an optical element. The motor has a housing and a motor body, and the housing is set to a side of a central axis of the motor body. The color filter is set on the housing of the motor. The motor body is fixed on the fixing element. A holder is formed on the fixing element, and the holder outwardly extends from the fixing element. The optical element is jointed with the holder. In addition, the invention also provides a color wheel assembly further including an auxiliary fixing element, which is set on the fixing element and has an outwardly extending holder with which the optical element is jointed.
The color wheel assembly of the invention has the outwardly extending holder to joint the color wheel with the optical element. Compared to the prior art, during the aligning step, the relative position between the color wheel and the optical element in this invention needs not to be adjusted using different clamping mechanisms. Instead, the relative position between the color wheel and the optical element is fixed by using the holder of the fixing element or the auxiliary fixing element, and only the relative position between the color wheel assembly and other optical devices of the projector needs to be adjusted. Consequently, the invention is laborsaving and timesaving in adjustment. Meanwhile, since no unnecessary clamping mechanism is needed, the dimension of the projector may be reduced, and the manufacturing cost may be further decreased. In addition, the alignment precision and reproducibility are also improved, and the overall quality of the projector is also improved.
Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.